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Abstract:

A filtered smoking article is provided, which includes a
tobacco-containing rod surrounded by a wrapping material; a filter
element surrounded by a plug wrap adjacent to the tobacco-containing rod;
and a tipping material securing the tobacco-containing rod to the filter
element, the tipping material overlying the plug wrap of the filter
element and a portion of the wrapping material of the tobacco-containing
rod, wherein at least one of the plug wrap, the tipping material, and the
wrapping material surrounding the tobacco-containing rod are secured by
an adhesive composition comprising a thermoplastic starch polymer. The
adhesive composition can include a blend of the thermoplastic starch
polymer with a second biodegradable polymer, such as polyvinyl alcohol,
aliphatic polyesters, aliphatic polyurethanes, cis-polyisoprene,
cis-polybutadiene, polyhydroxy alkanoates, polyanhydrides, and copolymers
and blends thereof.

Claims:

1. A filtered smoking article, comprising: a tobacco-containing rod
surrounded by a wrapping material; a filter element surrounded by a plug
wrap adjacent to the tobacco-containing rod; and a tipping material
securing the tobacco-containing rod to the filter element, the tipping
material overlying the plug wrap of the filter element and a portion of
the wrapping material of the tobacco-containing rod, wherein at least one
of the plug wrap, the tipping material, and the wrapping material
surrounding the tobacco-containing rod are secured by an adhesive
composition comprising a thermoplastic starch polymer.

2. The filtered smoking article of claim 1, wherein the adhesive
composition comprising the thermoplastic starch polymer is in the form of
a hot melt or an aqueous dispersion.

3. The filtered smoking article of claim 1, wherein the thermoplastic
starch polymer comprises about 30 to about 95 weight percent of starch
and about 5 to about 55 weight percent of one or more plasticizers.

4. The filtered smoking article of claim 1, wherein the thermoplastic
starch polymer further comprises up to about 20 weight percent of one or
more additional additives selected from the group consisting of
dispersion aids and colloids.

5. The filtered smoking article of claim 1, wherein the adhesive
composition comprises a blend of the thermoplastic starch polymer and a
second biodegradable polymer.

6. The filtered smoking article of claim 5, wherein the second
biodegradable polymer is selected from the group consisting of polyvinyl
alcohol, aliphatic polyesters, aliphatic polyurethanes, cis-polyisoprene,
cis-polybutadiene, polyhydroxy alkanoates, polyanhydrides, and copolymers
and blends thereof.

7. The filtered smoking article of claim 5, wherein the adhesive
composition comprises at least about 40 weight percent of the blend,
based on the total weight of the adhesive composition.

8. The filtered smoking article of claim 5, wherein the adhesive
composition comprises at least about 55 weight percent of the blend,
based on the total weight of the adhesive composition.

9. The filtered smoking article of claim 1, wherein the adhesive
composition comprises at least about 35 weight percent of the
thermoplastic starch polymer, based on the total weight of the adhesive
composition.

10. The filtered smoking article of claim 1, wherein the adhesive
composition comprises at least about 45 weight percent of the
thermoplastic starch polymer, based on the total weight of the adhesive
composition.

12. The filtered smoking article of claim 1, wherein the adhesive
composition secures the plug wrap and is in the form of a hot melt,
wherein the hot melt comprises at least about 35 weight percent of the
thermoplastic starch polymer.

13. The filtered smoking article of claim 1, wherein the adhesive
composition secures the tipping material and is in the form of an aqueous
dispersion, wherein the aqueous dispersion comprises at least about 35
weight percent of the thermoplastic starch polymer.

14. The filtered smoking article of claim 1, wherein the smoking article
is in the form of a cigarette or an aerosol-generating smoking article
that does not combust tobacco.

15. A filtered smoking article, comprising: a tobacco-containing rod
surrounded by a wrapping material; a filter element surrounded by a plug
wrap adjacent to the tobacco-containing rod; and a tipping material
securing the tobacco-containing rod to the filter element, the tipping
material overlying the plug wrap of the filter element and a portion of
the wrapping material of the tobacco-containing rod, wherein both the
plug wrap and the tipping material are secured by an adhesive composition
comprising at least about 35 weight percent of a thermoplastic starch
polymer.

16. The filtered smoking article of claim 15, wherein the adhesive
composition comprises a blend of the thermoplastic starch polymer and a
second biodegradable polymer.

17. The filtered smoking article of claim 16, wherein the second
biodegradable polymer is selected from the group consisting of polyvinyl
alcohol, aliphatic polyesters, aliphatic polyurethanes, cis-polyisoprene,
cis-polybutadiene, polyhydroxy alkanoates, polyanhydrides, and copolymers
and blends thereof.

17. The filtered smoking article of claim 15, wherein the adhesive
composition comprising the thermoplastic starch polymer is in the form of
a hot melt or an aqueous dispersion.

18. The filtered smoking article of claim 15, wherein the thermoplastic
starch polymer comprises about 30 to about 95 weight percent of starch
and about 5 to about 55 weight percent of one or more plasticizers.

Description:

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation-in-part of U.S. application Ser.
No. 12/827,618, filed Jun. 30, 2010, which is incorporated by reference
herein in its entirety.

FIELD OF THE INVENTION

[0002] The present invention relates to products made or derived from
tobacco, or that otherwise incorporate tobacco, and are intended for
human consumption. The invention is particularly directed to degradable
components for use in adhesive compositions for smoking article wrapping
materials.

BACKGROUND OF THE INVENTION

[0003] Popular smoking articles, such as cigarettes, have a substantially
cylindrical rod-shaped structure and include a charge, roll or column of
smokable material, such as shredded tobacco (e.g., in cut filler form),
surrounded by a paper wrapper, thereby forming a so-called "smokable rod"
or "tobacco rod." Normally, a cigarette has a cylindrical filter element
aligned in an end-to-end relationship with the tobacco rod. Typically, a
filter element comprises plasticized cellulose acetate tow circumscribed
by a paper material known as "plug wrap." Certain filter elements can
incorporate polyhydric alcohols. Typically, the filter element is
attached to one end of the tobacco rod using a circumscribing wrapping
material known as "tipping paper." It also has become desirable to
perforate the tipping material and plug wrap, in order to provide
dilution of drawn mainstream smoke with ambient air. Descriptions of
cigarettes and the various components thereof are set forth in Tobacco
Production, Chemistry and Technology, Davis et al. (Eds.) (1999). A
cigarette is employed by a smoker by lighting one end thereof and burning
the tobacco rod. The smoker then receives mainstream smoke into his/her
mouth by drawing on the opposite end (e.g., the filter end) of the
cigarette.

[0004] The discarded portion of the cigarette rod is primarily composed of
the filter element, which typically consists of tightly-compacted and
highly crimped cellulose acetate fibers bonded at their contact points
and wrapped by plug wrap and tipping paper. The presence of the wrapping
materials, the fiber-to-fiber bonding, and the compacted nature of
conventional filter elements have a detrimental effect on the rate of
degradation of cigarette filters in the environment. Unless the filter
element is unwrapped and the fibers spread apart to increase exposure,
biodegradation of the filter can take several years.

[0005] A number of approaches have been used in the art to promote an
increased rate of degradation of filter elements. One approach involves
incorporation of additives (e.g., water soluble cellulose materials,
water soluble fiber bonding agents, photoactive pigments, or phosphoric
acid) into the cellulose acetate material in order to accelerate polymer
decomposition. See U.S. Pat. Nos. 5,913,311 to Ito et al.; 5,947,126 to
Wilson et al.; 5,970,988 to Buchanan et al.; and 6,571,802 to Yamashita.
In some cases, conventional cellulose acetate has been replaced with
other materials, such as moisture disintegrative sheet materials,
extruded starch materials, or polyvinyl alcohol. See U.S. Pat. Nos.
5,709,227 to Arzonico et al; 5,911,224 to Berger; 6,062,228 to Loercks et
al.; and 6,595,217 to Case et al. Incorporation of slits into a filter
element has been proposed for enhancing biodegradability, such as
described in U.S. Pat. Nos. 5,947,126 to Wilson et al. and 7,435,208 to
Garthaffner. U.S. Pat. No. 5,453,144 to Kauffman et al. describes use of
a water sensitive hot melt adhesive to adhere the plug wrap in order to
enhance biodegradability of the filter element upon exposure to water.
U.S. Pat. No. 6,344,349 to Asai et al. proposes to replace conventional
cellulose acetate filter elements with a filter element comprising a core
of a fibrous or particulate cellulose material coated with a cellulose
ester to enhance biodegradability. U.S. Pat. Appl. Pub. No. 2009/0288669
to Hutchens suggests incorporation of degradable fiber materials into a
filter element.

[0006] There remains a need in the art for a filtered smoking article
exhibiting enhanced environmental degradation properties, particularly
where the smoking article can be manufactured with only minor
modification of conventional smoking article production equipment.

SUMMARY OF THE INVENTION

[0007] In one aspect, the present invention relates to a smoking article,
and in particular, a rod-shaped filtered smoking article (e.g., a
filtered cigarette). The smoking article includes a lighting end (i.e.,
an upstream end) and a mouth end (i.e., a downstream end). A mouth end
piece is located at the extreme mouth end of the smoking article, and the
mouth end piece allows the smoking article to be placed in the mouth of
the smoker to be drawn upon. The mouth end piece has the form of a filter
element, which typically comprises a fibrous tow filter material. The
smoking article also includes several wrapping materials. In particular,
the smoking article includes a wrapping material surrounding the
tobacco-containing rod and a plug wrap surrounding the filter element.
Still further, a tipping material secures the tobacco-containing rod to
the adjacent filter element, the tipping material overlying the plug wrap
of the filter element and a portion of the wrapping material of the
tobacco-containing rod. At least one of the plug wrap, the tipping
material, and the wrapping material surrounding the tobacco-containing
rod is secured by an adhesive composition comprising a thermoplastic
starch polymer. The use of thermoplastic starch polymers in the adhesive
compositions utilized in smoking articles can enhance degradation of the
smoking article by causing relatively quick release of the adhesive bonds
following disposal of the smoking article. As the adhesive bonds in a
wrapping material degrade, the wrapping material will release from the
underlying, enwrapped components of the smoking article, such as the
filter element, which can facilitate greater exposure of the underlying
components to the environment.

[0008] The form of the adhesive composition comprising the thermoplastic
starch polymer can vary, and exemplary forms include hot melts and
aqueous dispersions. In one embodiment, the thermoplastic starch polymer
comprises about 30 to about 95 weight percent of starch and about 5 to
about 55 weight percent of one or more plasticizers. The thermoplastic
starch polymer can further comprise up to about 20 weight percent of one
or more additional additives selected from the group consisting of
dispersion aids and colloids. The amount of thermoplastic starch polymer
in the adhesive composition can vary, but the adhesive composition
typically comprises at least about 35 weight percent or at least about 45
weight percent of the thermoplastic starch polymer, based on the total
weight of the adhesive composition.

[0009] Polymeric blends can be used in the adhesive compositions of the
invention, including blends of the thermoplastic starch polymer and a
second biodegradable polymer, such as polyvinyl alcohol, aliphatic
polyesters, aliphatic polyurethanes, cis-polyisoprene, cis-polybutadiene,
polyhydroxy alkanoates, polyanhydrides, and copolymers and blends
thereof. The amount of polymer blend in the adhesive composition can
vary, but the adhesive composition typically comprises at least about 40
weight percent or at least about 55 weight percent of the blend, based on
the total weight of the adhesive composition.

[0011] In one particular embodiment, the adhesive composition secures the
plug wrap and is in the form of a hot melt, wherein the hot melt
comprises at least about 35 weight percent of the thermoplastic starch
polymer. In another embodiment, the adhesive composition secures the
tipping material and is in the form of an aqueous dispersion, wherein the
aqueous dispersion comprises at least about 35 weight percent of the
thermoplastic starch polymer.

[0012] The nature, form, or type of smoking article can vary. Exemplary
smoking articles include those in the form of a cigarette or an
aerosol-generating smoking article that does not combust tobacco to any
significant degree.

[0013] In one advantageous embodiment, the invention provides a filtered
smoking article, comprising: a tobacco-containing rod surrounded by a
wrapping material; a filter element surrounded by a plug wrap adjacent to
the tobacco-containing rod; and a tipping material securing the
tobacco-containing rod to the filter element, the tipping material
overlying the plug wrap of the filter element and a portion of the
wrapping material of the tobacco-containing rod, wherein both the plug
wrap and the tipping material are secured by an adhesive composition
comprising at least about 35 weight percent of a thermoplastic starch
polymer. The thermoplastic starch polymer can be blended with other
polymers as noted above, and can be in the form of a hot melt or an
aqueous dispersion.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to assist the understanding of embodiments of the
invention, reference will now be made to the appended drawings, which are
not necessarily drawn to scale. The drawings are exemplary only, and
should not be construed as limiting the invention.

[0015] FIG. 1 is an exploded perspective view of a smoking article having
the form of a cigarette, showing the smokable material, the wrapping
material components, and the filter element of the cigarette;

[0016]FIG. 2 is a cross-sectional view of a smoking article showing the
various wrapping material components;

[0017]FIG. 3 is a cross-sectional view of a "two-up" cigarette rod prior
to bifurcation during the cigarette manufacturing process;

[0019] FIG. 5 illustrates exemplary regions where an adhesive composition
according to the invention can be applied to the surface of a tipping
material adapted for application to a two-up cigarette rod;

[0020] FIG. 6 is a perspective view of a plug wrap being applied to a
continuous filter rod during manufacture of a smoking article;

[0021] FIG. 7 is a schematic view of a portion of a cigarette
manufacturing process illustrating application of an adhesive composition
of the invention to a tipping material and application of the tipping
material to a two-up cigarette rod; and

[0022]FIG. 8 is a schematic view of a portion of a filter rod
manufacturing process illustrating application of an adhesive composition
of the invention to a plug wrap and application of the plug wrap to a
continuous filter rod.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] The present inventions now will be described more fully hereinafter
with reference to the accompanying drawing. The invention may be embodied
in many different forms and should not be construed as limited to the
embodiments set forth herein; rather, these embodiments are provided so
that this disclosure will satisfy applicable legal requirements. Like
numbers refer to like elements throughout. As used in this specification
and the claims, the singular forms "a," "an," and "the" include plural
referents unless the context clearly dictates otherwise.

[0024] The present invention provides adhesive compositions comprising at
least one degradable material, such as a biodegradable polymer, suitable
for adhering wrapping materials in a smoking article. Although the
present disclosure focuses on use of such compositions to adhere plug
wrap or tipping paper, certain embodiments of the adhesives of the
invention could be used to adhere other wrapping materials used in
smoking article manufacture, such as the wrapping material encasing a
tobacco rod. Accordingly, the invention is applicable to any wrapping
material or other component requiring adhesive used in the construction
of smoking articles or other tobacco products that do not combust tobacco
to any significant degree. The adhesive compositions of the invention
could also find use in certain smokeless tobacco products, such as use
for adhering seams of smokeless tobacco pouches or in other tobacco
product packaging applications.

[0025] The use of degradable materials in adhesive compositions used to
secure wrapping materials of smoking articles, such as cigarettes, can
increase or enhance the degradability of the smoking article itself.
Heretofore, conventional adhesive compositions used in smoking article
manufacture comprise relatively non-degradable polymeric materials such
as ethylene vinyl acetate.

[0026] In one aspect, the invention provides a plug wrap adhesive
composition or tipping paper adhesive composition comprising a degradable
polymer. In one embodiment, the biodegradable polymer is a thermoplastic
starch polymer or a blend containing such a starch polymer. As used
herein, "starch" or "starch polymer" refers to a is a
polysaccharide-based carbohydrate polymer (C6H10O.sub.5)n
comprising glucose units joined together by glycosidic linkages, and can
be characterized primarily as a mixture of linear (amylose) and branched
(amylopectin) polymers. Amylose is essentially a linear polymer of
α(1→4) linked D-glucopyranosyl units. Amylopectin is a
highly-branched polymer of D-glucopyranosyl units containing
α(1→4) linkages, with α(1→6) linkages at the
branch points. Naturally-occurring corn starch contains about 75%
amylopectin (higher molecular weight branched starch polymer) and 25%
amylose (lower molecular weight linear starch polymer), although hybrid
corn starch products containing more than 50% amylose are sold by
National Starch and Chemical Company Corporation and American Maize
Products Company. The amount of amylose and amylopectin within the starch
used in the present invention can vary, although the amylose content is
typically about 5% to about 90% by weight with the remainder being
amylopectin. Natural starch is a partially crystalline structure (e.g.,
about 15 to about 45% crystallinity) that is hydrophilic, with much of
the swelling in water occurring in the amorphous sections of the
molecule. Additional exemplary starch materials are described in U.S.
Pat. Nos. 5,780,568 to Vuorenpaa et al.; 6,011,092 to Seppala et al.;
6,369,215 to Pletonen et al.; 6,514,526 to Forssell et al.; 6,605,715 to
Lammers et al.; and 6,780,903 to Pletonen et al., and U.S. Pat. Appl.
Pub. Nos. 2005/0107603 to Pletonen et al. and 2006/0128889 to Mikkonen et
al., which are incorporated herein by reference in their entirety.
Exemplary weight average molecular weight ranges for the starch material
of the present invention can vary, but the molecular weight of the starch
is typically in the range of about 1,000 to about 3,000,000 Da, often
about 75,000 to about 1,000,000 Da, and more often about 150,000 to about
750,000 Da.

[0027] The starch may be used in its natural form (e.g., as extracted from
one or more plants, or as purified by any method), in a destructured
form, in any number of chemically modified derivative forms (e.g.,
hydroxyalkylated starch, starch esters, ionically modified starches
including cationic starch derivatives and anionic starch derivatives,
oxidized starches, plasticized starches, hydrolyzed starches, gelatinized
starch, grafted starches, crosslinked starches, transglycosylated
starches, starch ethers, or mixtures thereof). Certain modifications of
starch increase hydrophobicity of the material, which can be done without
departing from the invention. Although starch isolated and/or purified
from any plant sources may be useful in the present invention, exemplary
starch sources include corn, potato, tapioca, rice, oat, peas, sago,
barley, wheat, cassava, and yam. Starches produced from any source and
starches modified in any manner described herein are encompassed in the
present invention.

[0029] A thermoplastic starch polymer can also include other optional
components such as dispersion aids or protective colloids. Exemplary
optional colloids include polyvinyl alcohol, alkyl ether dimer, beeswax,
carnauba wax, and the like. Exemplary dispersion aids or surfactants
include polyoxyethylene derivatives (e.g., polysorbates), saponin, alkyl
sulfonates, alkyl benzene sulfonates, and the like. Additional
information regarding thermoplastic starches can be found, for example,
in U.S. Pat. Nos. 6,011,092 to Seppala et al. and 6,136,097 to Lorcks et
al; and U.S. Pat. Appl. Pub. Nos. 2009/0247036 and 2009/0305592 to Shi et
al., all of which are incorporated by reference herein.

[0030] The relative amount of starch material, plasticizer, and optional
additional components in a thermoplastic starch polymer composition can
vary. Typically, a thermoplastic starch polymer will contain from about
30 weight percent to about 95 weight percent of starch (including bound
water), from about 5 weight percent to about 55 weight percent of one or
more plasticizers, and from about 0.01 weight percent to about 20 weight
percent of any further optional components such as dispersion aids or
protective colloids, based on the total weigh of the polymer composition.

[0031] Exemplary commercial embodiments of thermoplastic starch that could
be used, or readily modified for use, in the present invention include
BIOMAX® TPS available from DuPont, BIOPLAST TPS® available from
Biotec GmbH, GETREX TP II available from IGV, PLANTIC® TPS available
from Plantic Technologies Limited, RE-NEW 400 starch resin available from
StarchTech, Inc., SOLANYL® BP available from Rodenburg Biopolymers
B.V., CEREPLAST COMPOSTABLES® available from Cereplast, Inc., and
BIOGRADE® TPS available from Biograde Ltd.

[0032] The TPS can be used as a singular polymer component in the adhesive
composition or admixed with one or more additional polymer materials.
When a polymer blend is used, the blending partners are also typically
degradable. Exemplary biodegradable polymers that could be blended with
TPS include polyvinyl alcohol, aliphatic polyesters, aliphatic
polyurethanes, cis-polyisoprene, cis-polybutadiene, polyhydroxy
alkanoates, polyanhydrides, and copolymers and blends thereof. The term
"aliphatic polyester" refers to polymers having the
structure--[C(O)--R--O]n--, wherein n is an integer representing the
number of monomer units in the polymer chain and R is an aliphatic
hydrocarbon, preferably a C1-C10 alkylene, more preferably a C1-C6
alkylene (e.g., methylene, ethylene, propylene, isopropylene, butylene,
isobutylene, and the like), wherein the alkylene group can be a straight
chain or branched. Exemplary aliphatic polyesters include polyglycolic
acid (PGA), polylactic acid (PLA) (e.g., poly(L-lactic acid) or
poly(DL-lactic acid)), polyhydroxy butyrate (PHB), polyhydroxy valerate
(PHV), polycaprolactone (PCL), and copolymers thereof. Other examples of
polymers suitable for blending with a starch material include
biodegradable thermoplastic polyesters such as Ecoflex®
aliphatic-aromatic copolyester materials available from BASF Corporation
or poly(ester urethane) polymers described in U.S. Pat. No. 6,087,465 to
Seppala et al., which is incorporated by reference herein in its
entirety. Although relatively non-degradable synthetic polymers, such as
certain aromatic polyesters (e.g., polyethylene terephthalate) or
polyolefins (e.g., polyethylene, polypropylene), could also be used in a
blend with TPS, the resulting adhesive composition would have decreased
biodegradability.

[0033] Exemplary commercial embodiments of thermoplastic starch blends
that could be used, or readily modified for use, in the present invention
include BIOLICE® blends (starch material combined with ECOFLEX®
copolyester polymer) available from Limagrain Cereales, BIOGRADE®
blends (TPS and aliphatic polyester or polyvinyl alcohol) available from
Biograde Ltd., CERELOY® blends (TPS and polyolefins) available from
Cerestech, Inc., GB blend series (TPS and biodegradable polyester)
available from Grace Biotech, MATER-BIO blends (TPS and polyvinyl
alcohol) available from Novamont SpA, BIOCERES® blends (wheat flour
and polyester) available from FuturaMat, CEREPLAST HYBRID RESINS®
(starch and polyolefin) and CEREPLAST COMPOSTABLES® (TPS and
polylactic acid) available from Cereplast, Inc., BIOPAR® blends (TPS
and copolyester) available from BIOP Biopolymer Technologies AG,
BIOPLAST® blends (TPS and aliphatic polyesters) available from Biotec
GmbH, NOVON® blends (starch and copolyester, polycaprolactone or
cellulose acetate) available from Warner-Lambert, and GREENPOL® blends
(starch and polycaprolactone) available from SK Corporation.

[0034] The relative amount of thermoplastic starch polymer or polymer
blend comprising a thermoplastic starch polymer in the adhesive
composition can vary. Typically, the TPS itself is present in the
adhesive composition at a concentration of at least about 35 weight
percent, often at least about 40 weight percent, and frequently at least
about 45 weight percent, based on the total weight of the adhesive
composition (e.g., at least about 50 weight percent or even at least
about 55 weight percent). Where a polymer blend is used, such as a blend
of TPS and a second biodegradable polymer, the concentration of the blend
is typically at least about 40 weight percent, based on the total weight
of the adhesive composition, and often at least about 50 weight percent
or at least about 55 weight percent. In certain embodiments, polymer
blend comprising a thermoplastic starch polymer accounts for at least
about 65 weight percent of the adhesive or at least about 75 weight
percent.

[0035] The adhesive composition can contain various further additives in
addition to those mentioned in connection with thermoplastic starch
polymers. Exemplary additives include tackifying resins (e.g., rosins,
terpenes, aliphatic, cycloaliphatic or aromatic resins, hydrogenated
hydrocarbon resins, and terpene-phenol resins), waxes, additional
plasticizers (e.g., benzoates, phthalates, and paraffin oils),
antioxidants and stabilizers (e.g. hindered phenols, butylated
hydroxytoluene (BHT), phosphates, and hindered aromatic amines), UV
stabilizers, pigments and dyes, biocides, flame retardants, antistatic
agents, fillers (e.g., calcium carbonate, barium sulfate, talc, silica,
carbon black, clays such as kaolin, and plant-derived fibrous materials
such as cotton, wool, cedar, hemp, bamboo, kapok, or flax), surfactants,
anti-foaming agents, and the like. Tackifying resins are typically used
in an amount of about 0 to about 50 weight percent, based on the total
weight of the adhesive composition. Waxes are typically used in an amount
of about 0 to about 40 weight percent. The remaining types of additives
are typically used in an amount of up to about 40 weight percent, often
up to about 25 weight percent, and more often up to about 10 weight
percent. Types of additives useful for adhesives used in cigarette
manufacture are also described in U.S. Pat. No. 5,453,144 to Kauffman et
al. and U.S. Pat. Appl. Pub. Nos. 2003/0027007 to Wieczorek, Jr. et al.
and 2006/0137700 to Gong et al., all of which are incorporated by
reference herein.

[0036] The adhesive composition comprising the thermoplastic starch
polymer or polymer blend comprising a thermoplastic starch polymer can be
used in a variety of forms depending on the application. For plug wrap
adhesive compositions, a hot melt formulation is typically used. As used
herein, hot melt refers to a polymeric adhesive composition that contains
little or no solvent content and which is solid at room temperature and
heated to form a liquid prior to application. For tipping paper adhesive
compositions, an adhesive composition in the form of an aqueous
dispersion is typically used. As used herein, an aqueous dispersion
refers to a polymeric adhesive composition wherein one or more polymeric
components are present as dispersed particles in water. Aqueous
dispersion adhesives typically become tacky when heated due to
evaporation of at least a portion of the aqueous solvent, and the
temperature at which the adhesive becomes tacky is generally referred to
as the activation temperature.

[0037] Many of the TPS and TPS-containing blends described above are
commercially available in a form suitable for use as a hot melt adhesive.
However, in certain embodiments, the commercially available TPS or
TPS-containing blend can be modified by blending with additional
plasticizers or tackifying agents prior to use as a hot melt adhesive. In
certain embodiments of the invention, a thermoplastic starch containing
adhesive composition is provided in hot melt form having a melting
temperature of about 60° C. to about 150° C., more often
about 65° C. to about 120° C., and most often about
70° C. to about 100° C. Viscosity of the hot melt adhesive
of the invention within its application temperature range can vary, but
is typically about 500 centipoise (cP) to about 50,000 cP, more often
about 800 cP to about 5,000 cP, and most often about 1,000 cP to about
3,500 cP. In certain advantageous embodiments, the hot melt adhesive of
the invention is capable of penetrating a paper substrate to form a
functional fiber tearing or suction bond adequate to maintain the
integrity of the adhesive bond for the expected life of the adhered
components.

[0038] To form an aqueous dispersion containing a TPS or TPS-containing
polymer blend, a commercially-available solid polymer product will
sometimes require conversion to an aqueous dispersion form using any of a
variety of techniques. For example, the polymer product can be first
dissolved in a water-miscible organic solvent and precipitated into the
form of a dispersion by mixing with water (i.e., a solvent-antisolvent
approach). In another embodiment, a dispersion is formed by dissolving
the polymer product in an organic solvent that is immiscible with water
and then spraying the solution into heated water to immediately evaporate
the organic solvent (i.e., evaporative precipitation). Finally, various
types of equipment can be used to introduce shear into the polymer
product to greatly reduce the particle size in order to prepare particles
capable of dispersion in water. Exemplary particle size reduction
techniques include wet ball milling (e.g., using a ball mill with
zirconium dioxide beads, silicon nitride beads, or polystyrene beads),
high pressure homogenization (e.g., forcing the polymer and an aqueous
medium through a piston gap homogenizer), microfluidic particle size
reduction, spray drying, and supercritical fluid particle size reduction.

[0039] In certain embodiments, an aqueous dispersion adhesive containing
TPS is provided having an activation temperature of about 60° C.
to about 150° C., more often about 65° C. to about
120° C., and most often about 70° C. to about 100°
C. Viscosity of the aqueous dispersion of the invention at ambient
temperature can vary, but is typically about 100 cP to about 10,000 cP,
more often about 200 cP to about 5,000 cP, and most often about 300 cP to
about 700 cP. Percent solids of the aqueous dispersion of the invention
typically ranges from about 25% to about 60% solids, more often about 35%
to about 55% solids, and most often about 47% to about 52% solids.

[0040] If rheology modifying dispersion aids are added to the aqueous
dispersion, the viscosity of the aqueous dispersion and the percent
solids of the aqueous dispersion could change. For such modified
embodiments, the viscosity range is typically about 500 cP to about
10,000 cP, more often about 1,000 cP to about 5,000 cP, and most often
about 2,500 cP to about 4,600 cP. In addition, for such modified
embodiments, the percent solids range is typically about 25% to about 60%
solids, more often about 35% to about 55% solids, and most often about
45% to about 50% solids. In certain advantageous embodiments, the aqueous
dispersion adhesive of the invention is capable of penetrating a paper
substrate to form a functional fiber tearing or suction bond adequate to
maintain the integrity of the adhesive bond for the expected life of the
adhered components.

[0041] In certain embodiments, the TPS or TPS-containing polymer blend
used in the present invention can be characterized as degradable, meaning
the polymer material is capable of undergoing degradation or
decomposition, for example through chemical reaction that breaks down the
particles into decomposition products, particularly under environmental
conditions associated with disposal of a smoking article. Degradable
materials include those materials classified as biodegradable and
compostable. In certain embodiments, adhesive compositions of the
invention that contain the TPS or TPS-containing polymer blend are also
characterized as degradable, such as biodegradable and/or compostable.

[0042] As used herein, the term "biodegradable" refers to a material that
degrades under aerobic and/or anaerobic conditions in the presence of
bacteria, fungi, algae, and other microorganisms to carbon
dioxide/methane, water and biomass, although materials containing
heteroatoms can also yield other products such as ammonia or sulfur
dioxide. "Biomass" generally refers to the portion of the metabolized
materials incorporated into the cellular structure of the organisms
present or converted to humus fractions indistinguishable from material
of biological origin. The term "compostable" is generally used to refer
to a material that degrades into carbon dioxide, water, inorganic
compounds and biomass at a rate comparable to other known compostable
materials, and which leaves no visible or toxic residue.

[0043] Degradability can be measured, for example, by placing a sample in
environmental conditions expected to lead to decomposition, such as
placing a sample in water, a microbe-containing solution, a compost
material, or soil. The degree of degradation can be characterized by
weight loss of the sample over a given period of exposure to the
environmental conditions. Exemplary rates of degradation for certain
adhesive embodiments of the invention include a weight loss of at least
about 20% after burial in soil for 60 days or a weight loss of at least
about 30% after 15 days of exposure to a typical municipal composter.
However, rates of degradation can vary widely depending on the type of
degradable particles used, the remaining composition of the filter
element, and the environmental conditions associated with the degradation
test. U.S. Pat. Nos. 5,970,988 to Buchanan et al. and 6,571,802 to
Yamashita provide exemplary test conditions for degradation testing. The
degradability of a plastic material also may be determined using one or
more of the following ASTM test methods: D5338, D5526, D5988, and D6400.

[0044] The present invention is directed to use of the above-noted
adhesive compositions during manufacture of smoking articles,
particularly during manufacture of cigarettes comprising a plug wrap and
tipping paper. Referring to FIG. 1, there is shown a smoking article 10
in the form of a cigarette and possessing certain representative
components of a smoking article of the present invention. The cigarette
10 includes a generally cylindrical rod 12 of a charge or roll of
smokable filler material contained in a circumscribing wrapping material
16. The rod 12 is conventionally referred to as a "tobacco rod." The ends
of the tobacco rod 12 are open to expose the smokable filler material.
The cigarette 10 is shown as having one optional band 22 (e.g., a printed
coating including a film-forming agent, such as starch, ethylcellulose,
or sodium alginate) applied to the wrapping material 16, and that band
circumscribes the cigarette rod in a direction transverse to the
longitudinal axis of the cigarette. That is, the band 22 provides a
cross-directional region relative to the longitudinal axis of the
cigarette. The band 22 can be printed on the inner surface of the
wrapping material (i.e., facing the smokable filler material), or less
preferably, on the outer surface of the wrapping material. Although the
cigarette can possess a wrapping material having one optional band, the
cigarette also can possess wrapping material having further optional
spaced bands numbering two, three, or more.

[0045] At one end of the tobacco rod 12 is the lighting end 18, and at the
mouth end 20 is positioned a filter element 26. The filter element 26
positioned adjacent one end of the tobacco rod 12 such that the filter
element and tobacco rod are axially aligned in an end-to-end
relationship, preferably abutting one another. Filter element 26 may have
a generally cylindrical shape, and the diameter thereof may be
essentially equal to the diameter of the tobacco rod. The ends of the
filter element 26 permit the passage of air and smoke therethrough.

[0046] A cross-sectional view of a smoking article configured as shown in
FIG. 1 is shown in FIG. 2. As shown therein, the filter element 26 is
circumscribed along its outer circumference or longitudinal periphery by
a layer of outer plug wrap 28. The plug wrap 28 is affixed to the filter
element 26 using an adhesive composition according to the invention.
Although only one section of filter material is shown in FIG. 2, other
filter element configurations with multiple segments and/or cavities
could be used without departing from the invention.

[0047] The filter element 26 is attached to the tobacco rod 12 using
tipping material 46 that circumscribes both the entire length of the
filter element 26 and an adjacent region of the tobacco rod 12. The inner
surface of the tipping material 46 is fixedly secured to the outer
surface of the plug wrap 28 and the outer surface of the wrapping
material 16 of the tobacco rod, using an adhesive composition according
to the invention, which affixes the filter element and the tobacco rod to
one another. The tipping material 46 typically extends over the entire
length of the filter element 26, and about 2 mm to about 6 mm, often
about 3 mm to about 5 mm, and frequently about 4 mm over the length of
the adjacent region of the tobacco rod 12.

[0048] A ventilated or air diluted smoking article can be provided with an
optional air dilution means, such as a series of perforations 30, each of
which extend through the tipping material and plug wrap. The optional
perforations 30 can be made by various techniques known to those of
ordinary skill in the art, such as laser perforation techniques.
Alternatively, so-called off-line air dilution techniques can be used
(e.g., through the use of porous paper plug wrap and pre-perforated
tipping paper). For cigarettes that are air diluted or ventilated, the
amount or degree of air dilution or ventilation can vary. Frequently, the
amount of air dilution for an air diluted cigarette is greater than about
10 percent, generally is greater than about 20 percent, often is greater
than about 30 percent, and sometimes is greater than about 40 percent.
Typically, the upper level for air dilution for an air diluted cigarette
is less than about 80 percent, and often is less than about 70 percent.
As used herein, the term "air dilution" is the ratio (expressed as a
percentage) of the volume of air drawn through the air dilution means to
the total volume and air and smoke drawn through the cigarette and
exiting the extreme mouth end portion of the cigarette.

[0049] The adhesive compositions of the invention can be incorporated into
conventional cigarette manufacturing processes, particularly
manufacturing processes configured to provide "two-up" cigarette rods.
Although other manufacturing processes could be modified to use the
adhesives of the invention, this disclosure will focus on two-up rod
manufacturing processes.

[0050] Referring to FIG. 3, there is shown a representative two-up
cigarette 60 that can be subdivided along hashed line 2-2 in order to
provide two filtered cigarettes 62, 64 that each have the structure set
forth in FIG. 2. To form a two-up cigarette 60, a two-up filter segment
70 is provided. The representative filter segment 70 comprises filter
material and is circumscribed by plug wrap 72. Two tobacco rods 12, 12'
are aligned at each end of the two-up filter segment to form a two-up
cigarette rod. A layer of tipping material 74 (e.g., a so-called "patch"
of tipping material) is wrapped around the aligned components, such that
the tipping material circumscribes the entire length of the two-up filter
segment 70, and a portion of the length of each tobacco rod 12, 12' in
the respective regions thereof adjacent the filter segment. As such, a so
called two-up cigarette 60 is provided. Optionally, that cigarette 60 can
be air diluted (e.g., using laser perforation techniques) by applying at
least one circumscribing ring of perforations 30, 30' through the tipping
material 74 and the underlying plug wrap 72. If desired, additional
layers of tipping material could be applied to form smoking articles with
multiple layers of tipping material as described in U.S. Pat. No.
7,789,089 to Dube et al., which is incorporated by reference herein. The
two-up combined filter segment 70 is ultimately cut in half along line
2-2 to provide two finished cigarettes 62, 64.

[0051] To prepare a filter rod for two-up cigarette rod manufacture, as
shown in FIG. 6, a continuous filter rod 80 of filter material is first
formed, wrapped with plug wrap 82, and subdivided into smaller segments
for use in the remainder of the manufacturing process. For example a
continuous filter rod 80 can be subdivided into segments appropriately
sized for use in a two-up manufacturing process. As illustrated in FIG.
6, adhesive 84 is applied to a seam of the plug wrap 82 so that the plug
wrap will adhere to itself upon wrapping of the plug wrap around the
continuous filter rod 80. Other regions of the plug wrap 82 could also be
treated with the adhesive 84 without departing from the invention. For
example, in certain embodiments, adhesive 84 is applied across the plug
wrap 82 perpendicular to the longitudinal axis of the continuous filter
rod 80 at certain intervals so that there is adhesive bonding directly to
the continuous filter rod 80 at spaced locations. In addition, the filter
rod 80 can be configured differently without departing from the
invention, such as by incorporation of cavities, smoke-altering materials
such as activated carbon, and the like.

[0052]FIG. 8 illustrates a simple schematic view of an apparatus for
applying plug wrap adhesive to a continuous filter rod 80. As shown, plug
wrap material 82 is supplied from roll 88 and passes through or by an
adhesive applicator 90. The applicator 90 can be configured to apply
adhesive in any manner and in any desired pattern. For example, the
applicator 90 can apply the adhesive only to a seam along the edge of the
plug wrap material 82 or can apply adhesive to any other desired
location. Exemplary types of applicators 90 that can be used include
applicators adapted for coating techniques such as knife-over-roll
coating, reverse roll coating, gravure coating, metering rod coating,
slot die coating, curtain coating, air knife coating, and the like. Since
plug wrap adhesive is typically in the form of a hot melt, the applicator
90 is typically a system particularly adapted for delivery of hot melt
adhesives, such as slot die or extrusion coating systems. Various methods
for specific placement of continuous and discontinuous adhesive seams
during manufacturing processes are commonly used. See, for example, U.S.
Pat. Nos. 4,252,527 to Hall; 6,021,782 to Seymour et al.; and 7,237,557
to Maiwald et al.; and U.S. Pat. Appl. Pub. No. 2009/0255835 to Pipes et
al., which are incorporated by reference herein.

[0053] Following application of the adhesive composition, the plug wrap 82
passes through an optional dryer 94, which may be unnecessary depending
on the form of the adhesive. For hot melt adhesives, a drying system is
typically not required. Where utilized, dryer 94 can comprise any known
drying system or apparatus adapted to evaporate solvent from the adhesive
coating, including conventional drying ovens. The dryer 94 can be
designed to dry either opposed surface or both surfaces of plug wrap 82.

[0054] Following the optional drying operation, the plug wrap can be
subjected to an optional microwave energy station 96 adapted to deliver
microwave energy to the adhesive composition applied to the plug wrap 82.
Microwave energy can enhance drying, activation or curing of the adhesive
and can be used in addition to, or in lieu of, a conventional dryer 94
(e.g., a conventional conductive heating system). The use of microwave
heating can provide shorter curing times and more efficient heating
through the application of microwave energy tuned to the most efficient
absorption frequencies for the adhesive material. Microwave energy
heating is independent of the thermal conductivity of the material being
heated. In conjunction with use of microwave energy, in certain
embodiments, the adhesive composition of the invention is formulated with
a polar additive, such as a salt material, to enhance the heating effect
derived from the microwave energy. Exemplary microwave heating systems
are available from Lambda Technologies of Morrisville, N.C. Microwave
heating systems are also described in U.S. Pat. Appl. Pub. No.
2007/0284034 to Fathi et al., which is incorporated by reference herein.
Although the microwave energy system 96 is shown positioned adjacent to
one surface of the plug wrap 82, the microwave energy can be delivered to
either side of the plug wrap or both sides if desired.

[0055] Following application of adhesive, the plug wrap 82 is placed in
contact with the continuous filter rod 80 and wrapped around the filter
rod in garniture 98. The presence of the adhesive causes the plug wrap to
remain securely fastened around the filter rod 80. Although not shown in
FIG. 8, the continuous filter rod is subdivided into smaller segments as
desired following the wrapping process.

[0056] Plug wrap adhesive applied in hot melt form is typically applied
through a heated nozzle at an application temperature of about
110° C. to about 160° C., and more often at an application
temperature of about 120° C. to about 130° C. Flow rate of
the adhesive is typically about 10 grams per minute measured at 500
meters per minute belt speed. Typically, line speed is about 225 to about
500 meters per minute belt speed, although in certain embodiments, belt
speeds of approximately half of the normal speed can be used. A cooling
bar (not shown) is typically provided to aid in setting the hot melt
adhesive, and the temperature of the cooling bar is typically set to
about 3° C. to about 5° C. Where an aqueous dispersion
adhesive is used for the plug wrap, application of the adhesive would
typically involve passing the adhesive through an extrusion nozzle at a
flow rate of about 10 to about 12 grams per minute measured at a belt
speed of about 500 meters per minute. Typically, line speeds would be
less than about 250 meters per minute belt speed and a heated seal bar
(not shown) can be used to aid setting of the aqueous dispersion
adhesive.

[0057] In a two-up cigarette rod process, a two-up filter rod is
positioned between two tobacco rods and a tipping material is wrapped
around the combined rod. In FIG. 4, a tipping sheet or patch 74 is shown
prior to being wrapped around a two-up rod that will be bifurcated along
line 2-2 into two cigarettes 62, 64. Manners and methods for applying
adhesives to tipping materials during automated cigarette manufacture
will be apparent to those skilled in the art of cigarette design and
manufacture. For example, a filtered cigarette can be tipped with a
tipping material in an essentially traditional manner using a Lab MAX
tipping device that is available from Hauni-Werke Korber & Co. KG.

[0058] FIG. 5 illustrates exemplary locations where adhesive can be
applied to tipping sheet 74. Any possible pattern of adhesive 100 can be
applied to the tipping sheet 74 without departing from the invention
including simply coating the entire underside of the sheet such that the
entire side of the tipping sheet adheres to the two-up cigarette rod.
Alternatively, the adhesive composition 100 can be applied to only
discrete locations on the tipping sheet 74, as illustrated in FIG. 5. In
the illustrated embodiment, adhesive 100 is applied to regions A, which
ensure that the tipping material is secured at the extreme mouth end of
the cigarette and at the end of the tipping material distal to the mouth
end after bifurcation along line 2-2 of the two-up rod. In certain
advantageous embodiments, the adhesive 100 is also applied in one or more
of regions B, which protects against delamination or puckering of the
tipping sheet 74 at the seam of the tipping sheet along the longitudinal
axis of the cigarette.

[0059] FIG. 7 illustrates a partial schematic view of a two-up cigarette
manufacturing process where a tipping paper sheet 74 is applied to the
two-up rod. As shown, a tipping paper 105 is withdrawn from a roll 110
and passes through or by an adhesive applicator 120, which can be any of
the types of applicators noted herein including applicators adapted for
knife-over-roll coating, reverse roll coating, gravure coating, metering
rod coating, slot die coating, curtain coating, air knife coating, and
the like. Following the adhesive application station 120, the tipping
paper 105 passes through or by an optional drying station 130, which can
consist of any known drying apparatus in the art, such as conventional
drying ovens. Whether the drying station is required will depend in part
on the type and form of adhesive composition 100 used. Since tipping
adhesive compositions 100 are typically used in aqueous dispersion form,
heat activation through drying is normally part of the process.
Accordingly, a dryer 130 would be expected where an aqueous dispersion
adhesive is used. The dryer 130 can be designed to dry either or both
surfaces of tipping paper 105. The process may also include an optional
microwave energy station 140 adapted to deliver microwave energy to the
adhesive composition 100 applied to the tipping material 105. The
microwave energy system 140 can direct microwave energy to either or both
sides of the tipping material 105 and is analogous to the microwave
system previously described in connection with the plug wrap adhesive
process.

[0060] Thereafter, the tipping paper 105 is directed onto a drum 150,
which typically applies a suction force to the tipping paper, and the
tipping paper passes rotary knife 160, where the paper material is sliced
into individual tipping sheets or patches 74. The tipping sheets 74 then
contacts unwrapped two-up cigarette rods 170 positioned in grooves of an
adjacent rotating drum 180. Each two-up rod 170 and tipping sheet 74 are
then passed to another drum 190, which brings the rods and tipping sheets
into contact with a rolling apparatus 200 that rolls the tipping material
around the two-up rod in order to complete the structure shown in FIG. 3.
The resulting wrapped two-up rods are then subjected to further
processing such as subdivision into individual cigarette rods (not
shown).

[0061] Typically, an aqueous dispersion adhesive is applied to a tipping
paper at ambient temperature using a metered applicator roller. Line
speeds are generally about 7,500 to about 12,000 cigarettes per minute
based on the machine and product being manufactured. Heat is often
applied to the tipping roll hand at a temperature setting of about
100° C.

[0062] The filter material can vary, and can be any material of the type
that can be employed for providing a tobacco smoke filter for cigarettes.
Preferably a traditional cigarette filter material is used, such as
cellulose acetate tow, gathered cellulose acetate web, polypropylene tow,
gathered cellulose acetate web, gathered paper, strands of reconstituted
tobacco, or the like. Especially preferred is filamentary or fibrous tow
such as cellulose acetate, polyolefins such as polypropylene, or the
like. One filter material that can provide a suitable filter rod is
cellulose acetate tow having 3 denier per filament and 40,000 total
denier. As another example, cellulose acetate tow having 3 denier per
filament and 35,000 total denier can provide a suitable filter rod. As
another example, cellulose acetate tow having 8 denier per filament and
40,000 total denier can provide a suitable filter rod. For further
examples, see the types of filter materials set forth in U.S. Pat. Nos.
3,424,172 to Neurath; 4,811,745 to Cohen et al.; 4,925,602 to Hill et
al.; 5,225,277 to Takegawa et al. and 5,271,419 to Arzonico et al.; each
of which is incorporated herein by reference.

[0063] Normally a plasticizer such as triacetin or carbowax is applied to
the filamentary tow in traditional amounts using known techniques. In one
embodiment, the plasticizer component of the filter material comprises
triacetin and carbowax in a 1:1 ratio by weight. The total amount of
plasticizer is generally about 4 to about 20 percent by weight,
preferably about 6 to about 12 percent by weight. Other suitable
materials or additives used in connection with the construction of the
filter element will be readily apparent to those skilled in the art of
cigarette filter design and manufacture. See, for example, U.S. Pat. No.
5,387,285 to Rivers, which is incorporated herein by reference.

[0064] The tipping material can vary, and exemplary materials are the
types conventionally used as tipping material in the manufacture of
cigarettes. Typical tipping materials are papers exhibiting relatively
high opacities. Representative tipping materials have TAPPI opacities of
greater than about 81 percent, often in the range of about 84 percent to
about 90 percent, and sometimes greater than about 90 percent. Typical
tipping materials are printed with inks, typically nitrocellulose based,
which can provide for a wide variety of appearances and "lip release"
properties. Representative tipping papers materials have basis weights
ranging from about 25 m/m2 to about 60 g/m2, often about 30
g/m2 to about 40 g/m2. Representative tipping papers are
available as Tervakoski Reference Nos. 3121, 3124, TK 652, TK674, TK675,
A360 and A362; and Schweitzer-Mauduit International Reference Nos. GSR270
and GSR265M2. See also, for example, the types of tipping materials, the
methods for combining cigarette components using tipping materials, and
techniques for wrapping various portions of cigarettes using tipping
materials, that are set forth in US Pat. Appl. Pub. Nos. 2007/0215167 to
Crooks et al. and 2009/0293894 to Cecchetto et al., which are
incorporated by reference herein.

[0065] The material use for the plug wrap can vary, and can include either
porous or non-porous paper material. Exemplary plug wrap papers ranging
in porosity from about 1,100 CORESTA units to about 26,000 CORESTA units
are available from Schweitzer-Maudit International as Porowrap 17-M1,
33-M1, 45-M1, 70-M9, 95-M9, 150-M4, 150-M9, 240M9S, 260-M4 and 260-M4T;
and from Miquel-y-Costas as 22HP90 and 22HP150. Non-porous plug wrap
materials typically exhibit porosities of less than about 40 CORESTA
units, and often less than about 20 CORESTA units. Exemplary non-porous
plug wrap papers are available from Olsany Facility (OP Paprina) of the
Czech Republic as PW646; Wattenspapier of Austria as FY/33060;
Miquel-y-Costas of Spain as 646; and Schweitzer-Mauduit International as
MR650 and 180. Plug wrap paper can be coated, particularly on the surface
that faces the filter material, with a layer of a film-forming material.
Such a coating can be provided using a suitable polymeric film-forming
agent (e.g., ethylcellulose, ethylcellulose mixed with calcium carbonate,
nitrocellulose, nitrocellulose mixed with calcium carbonate, or a
so-called lip release coating composition of the type commonly employed
for cigarette manufacture). Alternatively, a plastic film (e.g., a
polypropylene film) can be used as a plug wrap material. For example,
non-porous polypropylene materials that are available as ZNA-20 and
ZNA-25 from Treofan Germany GmbH & Co. KG can be employed as plug wrap
materials. See also, for example, U.S. Pat. No. 4,174,719 to Martin,
which is incorporated by reference.

[0066] The wrapping material used as the tipping material and the plug
wrap also can be constructed using a diffuse material (e.g., a diffuse
plug wrap or diffuse tipping material). In diffuse wrapping material
embodiments, the diffusivity of the wrapping material will most
preferably be similar to that of standard cigarette wrapping material
such as, for example, the material 16 (e.g., a diffusivity of about 2
cm/sec, or a base porosity of about 15 to about 80 CORESTA) or similar
materials of the type commonly used around a tobacco charge in a
cigarette. Exemplary embodiments will have a single layer of diffuse
tipping material and porous plug wrap. Diffuse wrapping material will be
greater than 0 CORESTA and less than 100 CORESTA, with a preferred range
between about 5 to about 80 CORESTA, and a diffusivity of at least about
1 cm/sec, preferably at least about 1.5 cm/sec. Diffusivity may be
measured using techniques such as, for example, those disclosed in US
Pat. Appl. Pub. No. 2005/0087202 to Norman et al., which is incorporated
herein by reference. This differs significantly from typical tipping or
plug wrap materials, which may provide little or no diffusivity (e.g.,
about 0 cm/sec, commonly less than about 1 cm/sec, or a base porosity of
less than about 10 CORESTA).

[0067] For cigarette embodiments including diffuse wrapping material
around the filter element, the wrapping material may be selected from a
number of paper or paper-like materials. In one example, a typical
wrapping material of the type commonly used to contain a tobacco charge
may be used. Such a wrapping material will most preferably include a
desirable diffusivity (e.g., sometimes greater than 1 cm/sec, preferably
greater than about 1.5 cm/sec, often about 1 to about 3 cm/sec, and
frequently about 2 cm/sec). Wrapping materials having a high degree of
diffusivity are described in US Pat. Appl. Pub. No. 2010/0108084 to
Norman et al., which is incorporated by reference herein in its entirety.
Although not bound by any particular theory of operation, it is believed
that the use of wrapping materials having a high degree of diffusivity
may provide advantageous flow characteristics through the filter element.

[0068] Various types of cigarette components, including tobacco types,
tobacco blends, top dressing and casing materials, blend packing
densities and types of paper wrapping materials for tobacco rods, can be
employed. See, for example, the various representative types of cigarette
components, as well as the various cigarette designs, formats,
configurations and characteristics, that are set forth in Johnson,
Development of Cigarette Components to Meet Industry Needs, 52nd
T.S.R.C. (September, 1998); U.S. Pat. Nos. 5,101,839 to Jakob et al.;
5,159,944 to Arzonico et al.; 5,220,930 to Gentry and 6,779,530 to
Kraker; US Pat. Appl. Pub. Nos. 2005/0016556 to Ashcraft et al.;
2005/0066986 to Nestor et al.; 2005/0076929 to Fitzgerald et al.;
2006/0272655 to Thomas et al.; 2007/0056600 to Coleman, III et al.; and
2007/0246055 to Oglesby, each of which is incorporated herein by
reference. Most preferably, the entire smokable rod is composed of
smokable material (e.g., tobacco cut filler) and a layer of
circumscribing outer wrapping material.

[0069] The adhesives of the present invention can also be used in filter
elements or other components incorporated within aerosol-generating
smoking articles that do not combust tobacco material to any significant
degree, such as those set forth in U.S. Pat. Nos. 4,756,318 to Clearman
et al.; 4,714,082 to Banerjee et al.; 4,771,795 to White et al.;
4,793,365 to Sensabaugh et al.; 4,989,619 to Clearman et al.; 4,917,128
to Clearman et al.; 4,961,438 to Korte; 4,966,171 to Serrano et al.;
4,969,476 to Bale et al.; 4,991,606 to Serrano et al.; 5,020,548 to
Farrier et al.; 5,027,836 to Shannon et al.; 5,033,483 to Clearman et
al.; 5,040,551 to Schlatter et al.; 5,050,621 to Creighton et al.;
5,052,413 to Baker et al.; 5,065,776 to Lawson; 5,076,296 to Nystrom et
al.; 5,076,297 to Farrier et al.; 5,099,861 to Clearman et al.; 5,105,835
to Drewett et al.; 5,105,837 to Barnes et al.; 5,115,820 to Hauser et
al.; 5,148,821 to Best et al.; 5,159,940 to Hayward et al.; 5,178,167 to
Riggs et al.; 5,183,062 to Clearman et al.; 5,211,684 to Shannon et al.;
5,240,014 to Deevi et al.; 5,240,016 to Nichols et al.; 5,345,955 to
Clearman et al.; 5,396,911 to Casey, III et al.; 5,551,451 to Riggs et
al.; 5,595,577 to Bensalem et al.; 5,727,571 to Meiring et al.; 5,819,751
to Barnes et al.; 6,089,857 to Matsuura et al.; 6,095,152 to Beven et al;
and 6,578,584 to Beven; and US Pat. Appl. Pub. Nos. 2010/0186757 to
Crooks et al. and 2011/0041861 to Sebastian et al., which are
incorporated herein by reference. Still further, filter elements of the
present invention can be incorporated within the types of cigarettes that
have been commercially marketed under the brand names "Premier" and
"Eclipse" by R. J. Reynolds Tobacco Company. See, for example, those
types of cigarettes described in Chemical and Biological Studies on New
Cigarette Prototypes that Heat Instead of Burn Tobacco, R. J. Reynolds
Tobacco Company Monograph (1988) and Inhalation Toxicology, 12:5, p. 1-58
(2000); which are incorporated herein by reference.

[0070] Cigarette rods typically are manufactured using a cigarette making
machine, such as a conventional automated cigarette rod making machine.
Exemplary cigarette rod making machines are of the type commercially
available from Molins PLC or Hauni-Werke Korber & Co. KG. For example,
cigarette rod making machines of the type known as MkX (commercially
available from Molins PLC) or PROTOS (commercially available from
Hauni-Werke Korber & Co. KG) can be employed. A description of a PROTOS
cigarette making machine is provided in U.S. Pat. No. 4,474,190 to Brand,
at col. 5, line 48 through col. 8, line 3, which is incorporated herein
by reference. Types of equipment suitable for the manufacture of
cigarettes also are set forth in U.S. Pat. Nos. 4,781,203 to La Hue;
4,844,100 to Holznagel; 5,131,416 to Gentry; 5,156,169 to Holmes et al.;
5,191,906 to Myracle, Jr. et al.; 6,647,870 to Blau et al.; 6,848,449 to
Kitao et al.; 6,854,469 to Hancock et al; 6,904,917 to Kitao et al.; and
7,677,251 to Barnes et al.; and US Pat. Appl. Pub. Nos. 2003/0145866 to
Hartman; 2004/0129281 to Hancock et al.; 2005/0039764 to Barnes et al.;
and 2005/0076929 to Fitzgerald et al.; each of which is incorporated
herein by reference.

[0071] The components and operation of conventional automated cigarette
making machines will be readily apparent to those skilled in the art of
cigarette making machinery design and operation. For example,
descriptions of the components and operation of several types of
chimneys, tobacco filler supply equipment, suction conveyor systems and
garniture systems are set forth in U.S. Pat. Nos. 3,288,147 to Molins et
al.; 3,915,176 to Heitmann et al.; 4,291,713 to Frank; 4,574,816 to
Rudszinat; 4,736,754 to Heitmann et al. 4,878,506 to Pinck et al.;
4,899,765 to Davis et al.; 5,060,665 to Heitmann; 5,012,823 to Keritsis
et al. and 6,360,751 to Fagg et al.; and US Pat. Appl. Pub. No.
2003/0136419 to Muller; each of which is incorporated herein by
reference. The automated cigarette making machines of the type set forth
herein provide a formed continuous cigarette rod or smokable rod that can
be subdivided into formed smokable rods of desired lengths.

[0072] Components for filter elements for filtered cigarettes typically
are provided from filter rods that are produced using traditional types
of rod-forming units, such as those available as KDF-2 and KDF-3E from
Hauni-Werke Korber & Co. KG. Typically, filter material, such as filter
tow, is provided using a tow processing unit. An exemplary tow processing
unit has been commercially available as E-60 supplied by Arjay Equipment
Corp., Winston-Salem, N.C. Other exemplary tow processing units have been
commercially available as AF-2, AF-3, and AF-4 from Hauni-Werke Korber &
Co. KG. In addition, representative manners and methods for operating a
filter material supply units and filter-making units are set forth in
U.S. Pat. Nos. 4,281,671 to Byrne; 4,862,905 to Green, Jr. et al.;
5,060,664 to Siems et al.; 5,135,008 to Oesterling et al.; 5,387,285 to
Rivers; and 7,074,170 to Lanier, Jr. et al.; and US Pat. Appl. Pub. Nos.
2010/0099543 to Deal and 2010/0192962 to Nelson et al., all of which are
incorporated by reference. Other types of technologies for supplying
filter materials to a filter rod-forming unit are set forth in U.S. Pat.
Nos. 4,807,809 to Pryor et al. and 5,025,814 to Raker; which are also
incorporated herein by reference.

[0073] Filter elements, or filter segment components of combination
filters, typically are provided from filter rods that are manufactured
using traditional types of cigarette filter rod making techniques. For
example, so-called "six-up" filter rods, "four-up" filter rods and
"two-up" filter rods that are of the general format and configuration
conventionally used for the manufacture of filtered cigarettes can be
handled using conventional-type or suitably modified cigarette rod
handling devices, such as tipping devices available as Lab MAX, MAX, MAX
S or MAX 80 from Hauni-Werke Korber & Co. KG. See, for example, the types
of devices set forth in U.S. Pat. Nos. 3,308,600 to Erdmann et al.;
4,238,993 to Brand et al.; 4,281,670 to Heitmann et al.; 4,280,187 to
Reuland et al.; 4,850,301 to Greene, Jr. et al.; 6,135,386 to
Garthaffner; 6,229,115 to Voss et al.; and 7,434,585 to Holmes, and US
Pat. Appl. Pub. Nos. 2005/1094014 to Read, Jr., and 2006/0169295 to
Draghetti, each of which is incorporated herein by reference. The
operation of those types of devices will be readily apparent to those
skilled in the art of automated cigarette manufacture.

[0074] Cigarette filter rods can be used to provide multi-segment filter
rods. Such multi-segment filter rods then can be employed for the
production of filtered cigarettes possessing multi-segment filter
elements. An example of a two-segment filter element is a filter element
possessing a first cylindrical segment incorporating activated charcoal
particles dispersed within cellulose acetate tow (e.g., a "dalmation"
type of filter segment) at one end, and a second cylindrical segment that
is produced from a filter rod produced essentially of flavored,
plasticized cellulose acetate tow filter material at the other end. The
production of multi-segment filter rods can be carried out using the
types of rod-forming units that traditionally have been employed to
provide multi-segment cigarette filter components. Multi-segment
cigarette filter rods can be manufactured using a cigarette filter rod
making device available under the brand name Mulfi from Hauni-Werke
Korber & Co. KG of Hamburg, Germany. Representative types of filter
designs and components, including representative types of segmented
cigarette filters, are set forth in U.S. Pat. Nos. 4,920,990 to Lawrence
et al.; 5,012,829 to Thesing et al.; 5,025,814 to Raker; 5,074,320 to
Jones et al.; 5,105,838 to White et al.; 5,271,419 to Arzonico et al.;
5,360,023 to Blakley et al.; 5,396,909 to Gentry et al.; and 5,718,250 to
Banerjee et al; US Pat. Appl. Pub. Nos. 2002/0166563 to Jupe et al.;
2004/0261807 to Dube et al.; 2005/0066981 to Crooks et al.; and
2007/0056600 to Coleman III, et al.; PCT Publication No. WO 03/009711 to
Kim; and PCT Publication No. WO 03/047836 to Xue et al.; which are
incorporated herein by reference.

[0075] The dimensions of a representative cigarette 10 can vary. Preferred
cigarettes are rod-shaped, and can have diameters of about 7.5 mm (e.g.,
circumferences of about 20 mm to about 27 mm, often about 22.5 mm to
about 25 mm); and can have total lengths of about 70 mm to about 120 mm,
often about 80 mm to about 100 mm. The length of the filter element 30
can vary. Typical filter elements can have total lengths of about 15 mm
to about 40 mm, often about 20 mm to about 35 mm. For a typical
dual-segment filter element, the downstream or mouth end filter segment
often has a length of about 10 mm to about 20 mm; and the upstream or
tobacco rod end filter segment often has a length of about 10 mm to about
20 mm.

[0076] The length of the filter element of each cigarette can vary.
Typically, the overall length of a filter element is about 20 mm to about
40 mm, and often about 25 mm to about 35 mm. For a typical dual-segment
filter element, the downstream or mouth end filter segment often has a
length of about 10 mm to about 20 mm; and the upstream or tobacco rod end
filter segment often has a length of about 10 mm to about 20 mm.

[0077] Preferred cigarettes of the present invention exhibit desirable
resistance to draw. For example, an exemplary cigarette exhibits a
pressure drop of between about 50 and about 200 mm water pressure drop at
17.5 cc/sec. air flow. Preferred cigarettes exhibit pressure drop values
of between about 60 mm and about 180, more preferably between about 70 mm
to about 150 mm, water pressure drop at 17.5 cc/sec. air flow. Typically,
pressure drop values of cigarettes are measured using a Filtrona
Cigarette Test Station (CTS Series) available form Filtrona Instruments
and Automation Ltd.

[0078] Many modifications and other embodiments of the invention will come
to mind to one skilled in the art to which this invention pertains having
the benefit of the teachings presented in the foregoing description; and
it will be apparent to those skilled in the art that variations and
modifications of the present invention can be made without departing from
the scope or spirit of the invention. Therefore, it is to be understood
that the invention is not to be limited to the specific embodiments
disclosed and that modifications and other embodiments are intended to be
included within the scope of the appended claims. Although specific terms
are employed herein, they are used in a generic and descriptive sense
only and not for purposes of limitation.